woo, i think i can actually answer this one. disable XPs preview function:
Configure which files WinXP should preview Post Comment
WinXP is very aggresive about being user friendly, and provides a nice preview feature for showing details and snapshots of pictures and movies. But if the media-file is flawed, then the preview feature starts to scan the entire file (F.ex. with AVI and MPG/MPEG files where the header or the index at the end of the file is broken). This can lead to high CPU usage and the file being locked, so when trying move or delete the file it gives the error:
Cannot delete/move <filename>: It is being used by another proson or program. Close any programs that might be using the file and try again
Disable preview for AVI files by deleting the (Default) in registry (Make a backup first):
[HKEY_CLASSES_ROOT \SystemFileAssociations \.avi \shellex \PropertyHandler]
(Default) = (Value not set)
Note to disable preview for other file-types just exchange the .avi with the wanted filetype and delete the (Default) for the wanted file-type.
Note if one likes the preview feature but just cannot delete a file then one can try:
Momentarily unregister shmedia.dll (Media File Property Extractor Shell Extension ) to delete the file:
regsvr32 /u shmedia.dll
(delete the file)
regsvr32 shmedia.dll
Rename the file so it no longer has the extension of a media file
Create a new folder and move the file into the new folder and delete the new folder
Close all explorer.exe and use the command-prompt.
Boot in safemode and delete the file, as the preview feature is disabled.
Note if have a directory containing many media files (Like mp3), then the preview feature will cause a slowdown when opening the folder, because it wants to extract information for each file.
Related Change Webview for all folders to stop movie preview
More Info MS KB 822430
Credits TweakXp.com
as posted by germanjulian
here